Question

是what about is your school trip?还是how is ...?为什么？

Answer 1

what about=how about都可以，句子中不需要加is，是习惯性短语的用法what about your school trip 你学校组织的旅行怎么样？

Answer 2

What about your school trip?
How about your school trip?
How is your school trip?
What is your school trip like?
询问某人对某事的看法，常用：
What/How about （doing）sth?
How is sth?
What is sth like?
注意点：what/how about后面直接加名词或代词，也可以加动ing，但不能加句子。